Ameloblastoma

Overview

Ameloblastoma is a rare, noncancerous (benign) tumor that develops most often in the jaw near the molars. Ameloblastoma begins in the cells that form the protective enamel lining on your teeth.

The most common type of ameloblastoma is aggressive, forming a large tumor and growing into the jawbone. Treatment may include surgery and radiation. In some cases, reconstruction may be necessary to restore your teeth, jaw and facial appearance. Some types of ameloblastoma are less aggressive.

Though ameloblastoma is most often diagnosed in adults in their 30s through 60s, ameloblastoma can occur in children and young adults.

Symptoms

Ameloblastoma often causes no symptoms, but signs and symptoms may include pain and a lump or swelling in the jaw.

If left untreated, the tumor can grow very large, distorting the shape of the lower face and jaw and shifting teeth out of position.

When to see a doctor

Talk to your dentist or health care provider if you have jaw swelling or pain or any other concerns with your oral health.

Causes

Ameloblastoma begins in the cells that form the protective enamel lining on your teeth. Rarely, it may start in gum tissue. The exact cause of the tumor is unclear, but several genetic changes (mutations) may be involved in the development of ameloblastoma. These changes may impact the location of the tumor, the type of cells involved and how fast the tumor grows.

Ameloblastomas are generally classified by type, but they can also be classified by cell type. The four main types include:

Conventional ameloblastoma. This is the most common type and grows aggressively, usually in the lower jawbone, and approximately 10% recur after treatment.
Unicystic ameloblastoma. This type is less aggressive, but typically occurs at a younger age. The tumor is often in the back of the lower jawbone at the molars. Recurrence is possible after treatment.
Peripheral ameloblastoma. This type is rare and affects the gums and oral tissue in the upper or lower jaw. The tumor has a low risk of recurrence after treatment.
Metastasizing ameloblastoma. This type is very rare and is defined by tumor cells that occur away from the primary site in the jaw.

Complications

Rarely, ameloblastoma can become cancerous (malignant). Very rarely, ameloblastoma cells can spread to other areas of the body (metastasize), such as the lymph nodes in the neck and lungs.

Ameloblastoma may recur after treatment.

Diagnosis

Ameloblastoma diagnosis might begin with tests such as:

Imaging tests. X-ray, CT and MRI scans help doctors determine the extent of an ameloblastoma. The tumor can sometimes be found on routine X-rays at the dentist's office.
Tissue test. To confirm the diagnosis, doctors may remove a sample of tissue or a sample of cells and send it to a lab for testing.

Treatment

Ameloblastoma treatment may depend on your tumor's size and location, and the type and appearance of the cells involved. Treatment may include:

Surgery to remove the tumor. Ameloblastoma treatment usually includes surgery to remove the tumor. Ameloblastoma often grows into the nearby jawbone, so surgeons may need to remove the affected part of the jawbone. An aggressive approach to surgery reduces the risk that ameloblastoma will come back.
Surgery to repair the jaw. If surgery involves removing part of your jawbone, surgeons can repair and reconstruct the jaw. This can help improve how your jaw looks and works afterward. The surgery can also help you to be able to eat and speak.
Radiation therapy. Radiation therapy using high-powered energy beams might be needed after surgery or if surgery isn't an option.
Prosthetics. Specialists called prosthodontists can make artificial replacements for missing teeth or other damaged natural structures in the mouth.
Supportive care. A variety of specialists can help you work through speaking, swallowing and eating problems during and after treatment. These specialists may include dietitians, speech and language therapists, and physical therapists.

Due to the risk of recurrence after treatment, lifelong, regular follow-up appointments are important.